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1 //===--- MacroArgs.h - Formal argument info for Macros ----------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file defines the MacroArgs interface.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_CLANG_MACROARGS_H
15 #define LLVM_CLANG_MACROARGS_H
16 
17 #include <vector>
18 
19 namespace clang {
20   class MacroInfo;
21   class Preprocessor;
22   class Token;
23   class SourceLocation;
24 
25 /// MacroArgs - An instance of this class captures information about
26 /// the formal arguments specified to a function-like macro invocation.
27 class MacroArgs {
28   /// NumUnexpArgTokens - The number of raw, unexpanded tokens for the
29   /// arguments.  All of the actual argument tokens are allocated immediately
30   /// after the MacroArgs object in memory.  This is all of the arguments
31   /// concatenated together, with 'EOF' markers at the end of each argument.
32   unsigned NumUnexpArgTokens;
33 
34   /// VarargsElided - True if this is a C99 style varargs macro invocation and
35   /// there was no argument specified for the "..." argument.  If the argument
36   /// was specified (even empty) or this isn't a C99 style varargs function, or
37   /// if in strict mode and the C99 varargs macro had only a ... argument, this
38   /// is false.
39   bool VarargsElided;
40 
41   /// PreExpArgTokens - Pre-expanded tokens for arguments that need them.  Empty
42   /// if not yet computed.  This includes the EOF marker at the end of the
43   /// stream.
44   std::vector<std::vector<Token> > PreExpArgTokens;
45 
46   /// StringifiedArgs - This contains arguments in 'stringified' form.  If the
47   /// stringified form of an argument has not yet been computed, this is empty.
48   std::vector<Token> StringifiedArgs;
49 
50   /// ArgCache - This is a linked list of MacroArgs objects that the
51   /// Preprocessor owns which we use to avoid thrashing malloc/free.
52   MacroArgs *ArgCache;
53 
MacroArgs(unsigned NumToks,bool varargsElided)54   MacroArgs(unsigned NumToks, bool varargsElided)
55     : NumUnexpArgTokens(NumToks), VarargsElided(varargsElided), ArgCache(0) {}
~MacroArgs()56   ~MacroArgs() {}
57 public:
58   /// MacroArgs ctor function - Create a new MacroArgs object with the specified
59   /// macro and argument info.
60   static MacroArgs *create(const MacroInfo *MI,
61                            const Token *UnexpArgTokens,
62                            unsigned NumArgTokens, bool VarargsElided,
63                            Preprocessor &PP);
64 
65   /// destroy - Destroy and deallocate the memory for this object.
66   ///
67   void destroy(Preprocessor &PP);
68 
69   /// ArgNeedsPreexpansion - If we can prove that the argument won't be affected
70   /// by pre-expansion, return false.  Otherwise, conservatively return true.
71   bool ArgNeedsPreexpansion(const Token *ArgTok, Preprocessor &PP) const;
72 
73   /// getUnexpArgument - Return a pointer to the first token of the unexpanded
74   /// token list for the specified formal.
75   ///
76   const Token *getUnexpArgument(unsigned Arg) const;
77 
78   /// getArgLength - Given a pointer to an expanded or unexpanded argument,
79   /// return the number of tokens, not counting the EOF, that make up the
80   /// argument.
81   static unsigned getArgLength(const Token *ArgPtr);
82 
83   /// getPreExpArgument - Return the pre-expanded form of the specified
84   /// argument.
85   const std::vector<Token> &
86     getPreExpArgument(unsigned Arg, const MacroInfo *MI, Preprocessor &PP);
87 
88   /// getStringifiedArgument - Compute, cache, and return the specified argument
89   /// that has been 'stringified' as required by the # operator.
90   const Token &getStringifiedArgument(unsigned ArgNo, Preprocessor &PP,
91                                       SourceLocation hashInstLoc);
92 
93   /// getNumArguments - Return the number of arguments passed into this macro
94   /// invocation.
getNumArguments()95   unsigned getNumArguments() const { return NumUnexpArgTokens; }
96 
97 
98   /// isVarargsElidedUse - Return true if this is a C99 style varargs macro
99   /// invocation and there was no argument specified for the "..." argument.  If
100   /// the argument was specified (even empty) or this isn't a C99 style varargs
101   /// function, or if in strict mode and the C99 varargs macro had only a ...
102   /// argument, this returns false.
isVarargsElidedUse()103   bool isVarargsElidedUse() const { return VarargsElided; }
104 
105   /// StringifyArgument - Implement C99 6.10.3.2p2, converting a sequence of
106   /// tokens into the literal string token that should be produced by the C #
107   /// preprocessor operator.  If Charify is true, then it should be turned into
108   /// a character literal for the Microsoft charize (#@) extension.
109   ///
110   static Token StringifyArgument(const Token *ArgToks,
111                                  Preprocessor &PP, bool Charify,
112                                  SourceLocation hashInstLoc);
113 
114 
115   /// deallocate - This should only be called by the Preprocessor when managing
116   /// its freelist.
117   MacroArgs *deallocate();
118 };
119 
120 }  // end namespace clang
121 
122 #endif
123